Plus is a port of Ninja Gaiden Sigma for the PlayStation Vita released in North America and Europe on February 22, 2012. Like Ninja Gaiden Blacks "Ninja Dog" mode, Sigma Plus features an easier difficulty called "Hero" mode, making it more accessible to casual gamers. It also takes advantage of the additional features that the Vita offers, including gyroscopic first-person aiming (by tilting the PlayStation Vita, the player can adjust the camera angle in first-person viewing modes), back touchpad controls (tapping symbols using the rear touchpad will allow Ryu to boost the power of his Ninpo), touch screen controls (players can go into first-person mode by tapping the touch screen). In addition, Ninja Gaiden Sigma Plus offers new sets of accessories that Ryu and Rachel can equip. ReceptionNinja Gaiden was released to critical acclaim. Greg Kasavin of GameSpot called it "one of the best most challenging action adventure games ever made", and his publication named it the best Xbox game of February 2004. IGN's Erik Brudvig said that it "sets a new standard for third-person action games in terms of length, depth, speed, and gore", while Electronic Gaming Monthly (EGM) called it "an unmissable instant classic", and declared that "no Xbox should go without [Ninja] Gaiden." Critics also regarded it to be one of the most difficult games released prior to 2007. The game received a runner-up position in GameSpot's 2004 "Best Action Adventure Game" category across all platforms. Its enhanced version, Ninja Gaiden Black, also impressed reviewers. GameSpot noted that it had the best visual and audio presentation on the Xbox, and praised its new Mission Mode for "[distilling] the game down to its purest essentials." IGN called its release "a rare and welcome day", which brought their "excitement levels back to the first time [they] played the game." From a technical point of view, critics regarded Ninja Gaiden and Black as the best of the available Xbox software at the time; the console hardware had been pushed to its limits without showing significant drops in performance. GameSpot's Kasavin was impressed with their "first-rate presentation" and said that no other games at that time came close in visuals and audio. According to IGN, the games could "make [them] momentarily forget about the next generation of consoles". Both Ninja Gaiden and Black were top-sellers, which led to them being compatible with the Xbox 360 for all regions on the new